Portable vacuum sampler

Abstract

The utility model discloses a portable vacuum sampler which comprises a box body and a box cover movably covering the box body, a control box is fixed on the outer wall of the box body, a vacuum pump is arranged in the control box, an air inlet of the vacuum pump is communicated with the inner space of the box body through a pipeline, the portable vacuum sampler further comprises a sampling header pipe, one end of the sampling header pipe is communicated with the outside atmosphere, and the other end of the sampling header pipe is communicated with the air outlet. A plurality of branch pipes are connected to the other end of the sampling header pipe, each branch pipe is used for being connected with a sampling bag, one-way valves are arranged on the sampling header pipe or each branch pipe, the flow direction of the one-way valves points to the sampling bags, an air pressure adjusting valve is further arranged on the side wall of the box body, and a partition plate is further arranged in the box body; the partition plates are used for separating the sampling bags connected with the branch pipes in the box body; the device has the advantages that multiple paths of samples can be simultaneously collected, sample gas is prevented from being sucked back, and sampling efficiency and data accuracy are effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a vacuum sampler, in particular to a portable vacuum sampler. BACKGROUND

[0002] The vacuum box sampler is a key equipment for monitoring volatile organic compounds (VOCs), oil gas and odor and other special gases on site. Its working mechanism is: the vacuum pump draws the inside of the box into negative pressure, and the pressure difference between the inside and outside of the box drives the measured gas to flow into the sampling bag automatically. This mode avoids direct contact and pollution of the sample by the pump body, and ensures the integrity of the sample. It is listed as the preferred device for monitoring unorganized emission in standards such as HJ732-2014.

[0003] The prior art such as the Chinese utility model with the announcement number CN215833094U discloses a novel vacuum box sampler, which comprises a box body, a sampling bag, a pressure gauge, a gas conveying pipe and a gas pump, a balance valve is arranged on the box cover of the vacuum box sampler, the gas pump is connected with the inside of the box body through a second valve to draw vacuum; the sampling bag is arranged in the box body and connected with a first valve (i.e. a sampling port) arranged on the box wall through a first gas conveying pipe; when sampling, the external gas enters the sampling bag through the first valve under the action of atmospheric pressure; after sampling is completed, the cover is opened for replacement.

[0004] However, the above-mentioned device has obvious defects in actual application. Firstly, the sampling efficiency is low: only one first valve (sampling port) and one first gas conveying pipe are arranged in the structure, and one sample can be collected in one sampling process (vacuumizing, sampling, pressure relief and bag taking), so the operator must repeat the complete process many times in the monitoring task of parallel sample comparison or multi-point arrangement, which greatly prolongs the on-site working time. Secondly, the sample backflow loss is serious: after sampling is completed, the operator must manually open the balance valve or directly open the cover for pressure relief, which makes the strong negative pressure in the box recover to normal pressure instantaneously, the pressure difference between the inside and outside of the bag is reversed, the pipeline from the first valve to the sampling bag is open and lacks automatic cutoff function, which causes the collected sample gas to be instantaneously backflowed and discharged, and the accuracy of low-concentration analysis is seriously affected. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a portable vacuum sampler which can collect multiple samples simultaneously and prevent sample gas backflow, and effectively improve the sampling efficiency and data accuracy.

[0006] In order to achieve the above object, the utility model provides the following technical scheme: A portable vacuum sampler, including box body and movable lid that closes on the box body lid, the outer wall of the box body is fixed with control box, the control box is provided with vacuum pump, the air inlet of vacuum pump is connected with the inside space of the box body through pipeline, still include sampling main pipe, one end of sampling main pipe is connected with outside atmosphere, the other end of sampling main pipe is connected with a plurality of branch pipes, every branch pipe is used for connecting a sampling bag, and sampling main pipe or every branch pipe is provided with check valve, the flow direction of check valve points to sampling bag, the lateral wall of the box body is also provided with air pressure regulating valve, the box body is also provided with baffle, the baffle is used for separating the sampling bag connected with a plurality of branch pipes in the box body.

[0007] Preferably, the baffle is a one-letter-shaped, cross-shaped baffle or a cross-shaped baffle, which divides the internal space of the box into a plurality of compartments for independently containing the sampling bag.

[0008] Preferably, the control box is further provided with a pressure sensor and a control circuit, the pressure sensor is used for monitoring the pressure value in the box in real time, the control circuit is electrically connected with the vacuum pump and the pressure sensor respectively, and the control circuit is configured to stop the work of the vacuum pump when the pressure sensor monitors that the box reaches a preset negative pressure value.

[0009] Preferably, the control box is further provided with a battery for supplying power to the vacuum pump, and the wall of the control box is further provided with a charging interface for charging the battery.

[0010] Preferably, the upper end of the box cover or the lateral wall of the box body is provided with a pressure gauge for monitoring the pressure in the box in real time.

[0011] Preferably, the box cover and the box body are locked and connected through at least two locking units, each locking unit comprises a lock catch fixed on the front side wall of the box cover and a lock seat fixed on the front side wall of the box body, and the lock catch is matched and buckled with the corresponding lock seat.

[0012] Preferably, the top end of the box body is provided with a ring-shaped sealing groove, the elastic sealing ring is embedded in the sealing groove, and the bottom edge of the box cover is pressed against the elastic sealing ring.

[0013] Preferably, the box body is made of acrylic material.

[0014] Preferably, the lateral wall of the box body is fixed with a tower joint, and the tower joint is communicated with the sampling main pipe.

[0015] Preferably, each of the branch pipes is detachably fitted with a cap at its end, the cap being used to seal the end of the branch pipe when it is not connected to the sampling bag.

[0016] Compared with existing technologies, the advantages of this utility model are as follows: multiple branch pipes connected to the sampling main pipe, combined with the partitions set inside the box, realize the synchronous collection and safe separation of multiple samples; the vacuum pump is integrated into the control box fixed to the outer wall of the box and connected to the inside of the box through pipelines, forming a compact integrated design for easy overall carrying; the one-way valves on the sampling main pipe or multiple branch pipes can effectively prevent sample backflow. When the vacuum pump stops working, the operator can slowly balance the pressure difference inside and outside the box through the air pressure regulating valve. During this process, the one-way valve can block the airflow backflow, thereby effectively preventing sample backflow and ensuring sampling accuracy. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 2 ;

[0020] Figure 3 This is a three-dimensional structural diagram of the sampling main tube, branch tubes, and sampling bag in this utility model.

[0021] Figure 4 This is a schematic block diagram of the circuit part of this utility model;

[0022] In the diagram, 1. Box body; 2. Box cover; 3. Control box; 4. Vacuum pump; 5. Sampling main pipe; 6. Branch pipe; 7. Sampling bag; 8. One-way valve; 9. Pressure regulating valve; 10. Partition; 11. Pressure sensor; 12. Control circuit; 13. Battery; 14. Charging interface; 15. Pressure gauge; 16. Locking unit; 17. Locking fastener; 18. Lock seat; 20. Elastic sealing ring; 21. Pagoda connector; 22. Plug cap. Detailed Implementation

[0023] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the content of the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] Example 1: As Figures 1-4 As shown, a portable vacuum sampler includes a housing 1 and a cover 2 that is movably closed onto the housing 1. A control box 3 is fixed on the outer wall of the housing 1. A vacuum pump 4 is installed inside the control box 3. The air inlet of the vacuum pump 4 is connected to the internal space of the housing 1 through a pipeline. The sampler also includes a sampling main pipe 5. One end of the sampling main pipe 5 is connected to the outside atmosphere. Multiple branch pipes 6 are connected to the other end of the sampling main pipe 5. Each branch pipe 6 is used to connect a sampling bag 7. A one-way valve 8 is installed on the sampling main pipe 5 or on each branch pipe 6. The flow direction of the one-way valve 8 is towards the sampling bag 7. A pressure regulating valve 9 is also installed on the side wall of the housing 1. A partition 10 is also installed inside the housing 1. The partition 10 is used to separate the sampling bags 7 connected to the multiple branch pipes 6 inside the housing 1.

[0025] When using this portable vacuum sampler, the operator first opens the box cover 2 and connects multiple sampling bags 7 to the multiple branch pipes 6 that branch off from the sampling main pipe 5. The partition 10 inside the box 1 ensures that these sampling bags 7 are effectively separated during the sampling process and do not interfere with each other.

[0026] After the operator closes the box cover 2, they start the vacuum pump 4, which is fixed in the control box 3 on the outer wall of the box 1. The vacuum pump 4 draws air from inside the box 1 (i.e., outside the sampling bag 7) through the pipeline, quickly creating a negative pressure inside the box 1. Driven by the pressure difference inside and outside the box 1, the gas to be tested from the outside automatically flows in through the sampling main pipe 5.

[0027] The advantage of this scheme is that when the gas flows to the sampling bag 7, it must pass through the one-way valve 8. The structural characteristics of the one-way valve 8 determine that it only allows the gas to flow in one direction (i.e., towards the sampling bag 7). When sampling is completed, the vacuum pump 4 stops working, or the operator begins to depressurize, the pressure inside the chamber 1 begins to rise. Once the pressure inside the sampling bag 7 or the branch pipe 6 is equal to or higher than the pressure at the inlet of the sampling main pipe 5, any gas attempting to flow out in the opposite direction will be automatically blocked by the structure of the one-way valve 8. It is this one-way conduction physical characteristic that fundamentally eliminates the possibility of sample gas backflow and ensures the integrity of the sample.

[0028] On this basis, the air pressure regulating valve 9 on the side wall of the box 1 plays a key auxiliary and optimization role, which allows the operator to make the external air slowly and controllably flow into the box 1 instead of instant impact. This slow pressure rising mode avoids the impact of the sudden pressure change on the one-way valve 8, ensures that the one-way valve 8 can stably and reliably realize reverse cutoff, and protects the safety of the box 1 and the sampling bag 7. Finally, the operator can safely open the box cover 2 to take the bag under normal pressure.

[0029] Embodiment two: as shown in the figure, different from embodiment one, the partition plate 10 is a horizontal plate, a cross-shaped partition plate or a cross-shaped partition plate, which divides the internal space of the box 1 into multiple compartments for independently containing the sampling bag 7. Figures 1-4

[0030] In a preferred embodiment of the utility model, the specific structure of the partition plate 10 is a horizontal plate, a cross-shaped partition plate or a cross-shaped partition plate, which physically divides the internal space of the box 1 into multiple compartments for independently containing the sampling bag 7. The beneficial effects of this design are that it ensures that multiple sampling bags 7 have independent containing spaces during vacuumizing and inflation, effectively avoids uneven inflation or sampling failure caused by mutual extrusion, folding or adhesion between the bag bodies (especially under high humidity conditions); the rigid compartment structure also effectively limits and stabilizes the sampling bag 7, significantly reduces the risk of the gas nozzle of the sampling bag 7 loosening and falling off from the branch pipe 6 due to violent shaking under the impact of transportation vibration or pressure relief air flow, and reduces the friction damage of the bag wall.

[0031] In this embodiment, the control box 3 is also provided with a pressure sensor 11 and a control circuit 12. The pressure sensor 11 is used to monitor the pressure value in the box 1 in real time, and the control circuit 12 is electrically connected with the vacuum pump 4 and the pressure sensor 11 respectively. The control circuit 12 is set to stop the work of the vacuum pump 4 when the pressure sensor 11 monitors that the preset negative pressure value in the box 1 is reached.

[0032] The core advantage of this structure is that the control circuit 12 is set as an automatic feedback system: when the pressure sensor 11 monitors that the negative pressure in the box 1 reaches the negative pressure value preset by the operator, the control circuit 12 will immediately automatically cut off the power supply of the vacuum pump 4 to stop its work. This design releases the operator from the tedious manual monitoring of the pressure gauge 15, realizes the automatic pump stopping at a constant pressure, ensures that the initial negative pressure condition of each sampling is completely consistent, improves the standardization degree of sampling, and effectively prevents the sampling bag 7 from being broken or the vacuum pump 4 from being overloaded due to excessive vacuumizing, significantly improves the safety and reliability of the equipment.

[0033] ​In this embodiment, the control box is also provided with a battery 13 for powering the vacuum pump 4, and the wall of the control box 3 is also provided with a charging interface 14 for charging the battery 13.

[0034] In order to realize the true portability of the device and field passive operation, the control box 3 is also specially provided with a battery 13 for powering the vacuum pump 4, which makes the sampler free from dependence on external power supply, and the operator does not need to carry additional power supply unit when working on site, and only with the device itself, the vacuum pump 4 can be started to complete sampling in any environment (such as high altitude, field or no power plant area), at the same time, the wall of the control box 3 is also provided with a charging interface 14, and the operator can conveniently supplement the power of the built-in battery 13 after the sampling task is completed, which ensures the reusability and endurance of the device, and makes it a highly integrated, self-sufficient portable sampling system.

[0035] In this embodiment, a pressure gauge 15 is provided on the upper end of the box cover 2 or the side wall of the box body 1 for real-time monitoring of the pressure in the box body 1.

[0036] The pressure gauge 15 is provided on the upper end of the box cover 2 or the side wall of the box body 1, and its core function is to provide real-time and intuitive visual feedback to the operator about the pressure in the box body 1. During the vacuuming stage, the operator can intuitively judge the working state of the vacuum pump 4 and the sealing performance of the entire system through the data change of the pressure gauge 15. After depressurization through the air pressure regulating valve 9 when the sampling is completed and the bag needs to be quickly taken out, the operator can confirm that the negative pressure in the box body 1 has been completely released and the pressure has returned to the state of balance with the external atmospheric pressure by observing the reading of the pressure gauge 15, and then the box cover 2 can be safely opened. This step ensures the safety of the operation and effectively avoids the difficulties caused by forcibly opening the cover when the box body 1 is still under negative pressure, or the damage to the device or the sample caused by instantaneous air flow impact.

[0037] In this embodiment, the box body 1 and the box cover 2 are connected by at least two locking units 16, each locking unit 16 includes a lock catch 17 fixed on the front side wall of the box cover 2 and a lock seat 18 fixed on the front side wall of the box body 1, and the lock catch 17 is adapted to be buckled with the corresponding lock seat 18.

[0038] In the above structure, at least two locking units 16 are used instead of a single locking unit, the purpose of which is to enable the box cover 2 to uniformly apply locking force to the elastic sealing ring 20 on the opening edge of the box body 1 when closed. This uniform pre-tightening pressure is a necessary prerequisite for establishing a reliable initial vacuum seal, which can effectively prevent leakage caused by poor sealing during the initial vacuuming stage.

[0039] In addition, the locking fastener 17 is fixed to the front side wall of the cover 2, and the locking seat 18 is fixed to the front side wall of the housing 1. The two are matched and locked together, providing a stable, strong locking force and convenient operation. This structure ensures that the cover 2 can still be firmly locked during transportation or under normal pressure after depressurization, thus ensuring the safety and integrity of the equipment.

[0040] In this embodiment, for ease of carrying, a shoulder strap is provided on the case 1, or a handle is provided on the upper end of the case lid 2.

[0041] In this embodiment, an annular sealing groove is provided at the top opening edge of the box body 1, and an elastic sealing ring 20 is embedded in the sealing groove. The bottom edge of the box cover 2 abuts against the elastic sealing ring 20.

[0042] The annular sealing groove set at the top opening edge of the housing 1 serves as a key feature, providing precise positioning and a stable mounting base for the elastic sealing ring 20. This embedded design effectively prevents the elastic sealing ring 20 from shifting, twisting, or falling off when the housing cover 2 is closed or the equipment vibrates, ensuring the reliability and consistency of the seal.

[0043] When the lid 2 is closed, its bottom edge is evenly pressed against the elastic sealing ring 20 (this pressure is usually provided by the locking unit 16). The elastic sealing ring 20 undergoes elastic deformation after being pressed, fully filling the tiny gap between the sealing groove and the bottom edge of the lid 2. At the same time, the side wall of the sealing groove also protects the sealing ring from excessive compression or shear damage from the edge of the lid 2, extending its service life.

[0044] Example 3: Figures 1-4 As shown, unlike Embodiment 2, the box 1 is made of acrylic material, which makes the box 1 itself a viewing window. During the sampling process, the operator can observe the filling status of multiple sampling bags 7 inside the box 1, whether the pipeline has fallen off, and whether the partition 10 is stable, etc., in real time and clearly from the side without opening the box cover 2. This greatly improves the reliability of sampling and effectively prevents the sampling task from failing due to overfilling, rupture or connection failure of the sampling bags 7.

[0045] Compared to glass or metal, acrylic is significantly lighter, which greatly reduces the overall weight of the equipment and effectively reduces the burden on field personnel.

[0046] In this embodiment, a pagoda connector 21 is fixed on the side wall of the housing 1, and the pagoda connector 21 is connected to the sampling manifold 5. The pagoda connector 21 is fixed on the side wall of the housing 1, providing a stable and standardized connection point outside the equipment, and its inner end is directly connected to the sampling manifold 5 inside the housing 1, forming the core inlet of the sample gas.

[0047] The main advantage of this particular form of the spigot 21 is that the multi-stage tower-like annular projections on the outer surface of the spigot are able to form a tight and reliable interference fit with the inner wall of the external sampling hose. This makes the field connection operation extremely convenient and fast, as the operator only needs to sleeve the hose, while this structure ensures that the connection has a very high airtightness and provides strong anti-pullout capability, effectively preventing the ambient air from leaking into the sampling manifold 5 from the interface during sampling, thus ensuring the representativeness and accuracy of the collected sample.

[0048] In this embodiment, a cap 22 is detachably mounted at the end of each branch pipe 6, and is used to seal the end of the branch pipe 6 when the branch pipe 6 is not connected to a sampling bag 7.

[0049] However, in actual sampling tasks, the operator may only need to collect one or less than the total number of samples of the branch pipes 6, in which case if the end of the unused branch pipe 6 remains open, it will become a serious leakage path when the vacuum pump 4 is working. Ambient air will be directly sucked into the box 1 from the open end, rather than through the sampling manifold 5, which will prevent the box 1 from establishing an effective negative pressure environment, and thus the sampling bags 7 connected to other branch pipes 6 will also not be able to sample normally, resulting in the failure of the entire sampling task.

[0050] Therefore, the utility model sets a detachable cap 22 at the end of each branch pipe 6, which can be used by the operator to seal the end of the branch pipe 6 when it is not connected to a sampling bag 7. This structure ensures that the airtightness of the entire vacuum system is maintained regardless of whether one or more branch pipes 6 are used, so that the vacuum pump 4 can normally establish a negative pressure.

[0051] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the contents of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A portable vacuum sampler comprising a box body and a box cover movably combined on the box body, a control box is fixed on the outer wall of the box body, a vacuum pump is arranged in the control box, and an air inlet of the vacuum pump is connected with an internal space of the box body through a pipeline, characterized in that: The sampling main pipe is communicated with the outside atmosphere at one end and connected with a plurality of branch pipes at the other end, each of the branch pipes is used for connecting a sampling bag, and a one-way valve is arranged on the sampling main pipe or each of the branch pipes, a flow direction of the one-way valve is directed to the sampling bag, an air pressure adjusting valve is further arranged on the side wall of the box body, a partition plate is further arranged in the box body, and the partition plate is used for separating the sampling bags connected with the plurality of branch pipes in the box body.

2. A portable vacuum sampler according to claim 1, wherein: The partition plate is a horizontal line-shaped, cross-shaped or checkered-shaped partition plate, which separates the internal space of the box body into a plurality of compartments for independently accommodating the sampling bags.

3. The portable vacuum sampler of claim 1, wherein: The control box is further provided with a pressure sensor and a control circuit, the pressure sensor is used for monitoring the pressure value in the box body in real time, the control circuit is electrically connected with the vacuum pump and the pressure sensor respectively, and the control circuit is arranged to stop the work of the vacuum pump when the pressure sensor monitors that the box body reaches a preset negative pressure value.

4. A portable vacuum sampler according to claim 3, wherein: The control box is further provided with a storage battery for supplying power to the vacuum pump, and the wall of the control box is further provided with a charging interface for charging the storage battery.

5. The portable vacuum sampler of claim 1, wherein: The upper end of the box cover or the side wall of the box body is provided with a pressure gauge for monitoring the pressure in the box body in real time.

6. The portable vacuum sampler of claim 1, wherein: The box body and the box cover are locked and connected through at least two locking units, each of the locking units comprises a lock catch fixed on the front side wall of the box cover and a lock seat fixed on the front side wall of the box body, and the lock catch is matched and buckled with the corresponding lock seat.

7. The portable vacuum sampler of claim 1, wherein: The top end opening edge of the box body is provided with an annular sealing groove, an elastic sealing ring is embedded in the sealing groove, and the bottom edge of the box cover is pressed against the elastic sealing ring.

8. The portable vacuum sampler of claim 1, wherein: The box body is made of acrylic material.

9. The portable vacuum sampler of claim 1, wherein: A tower joint is fixed on the side wall of the box body and communicated with the sampling main pipe.

10. The portable vacuum sampler of claim 1, wherein: A plug cap is detachably mounted at the end of each of the branch pipes, and the plug cap is used for sealing the end of the branch pipe when the branch pipe is not connected with the sampling bag.

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